Commit Graph

14 Commits

Author SHA1 Message Date
David Howells
7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Richard Knutsson
6e21828743 [PATCH] Generic boolean
This patch defines:
* a generic boolean-type, named 'bool'
* aliases to 0 and 1, named 'false' and 'true'

Removing colliding definitions of 'bool', 'false' and 'true'.

Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:18 -07:00
Mauro Carvalho Chehab
fb0b664c22 V4L/DVB (4344): Fix broken dependencies on media Kconfig
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-07-29 17:22:31 -03:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Jesper Juhl
bafefc0cf8 V4L/DVB (4154): Fix use-after-free bug in cpia2 driver
The coverity checker detected a use-after-free error in
drivers/media/video/cpia2/cpia2_v4l.c::cpia2_close() (coverity
error #1281).
What happens is that we lock cam->busy_lock, then proceed to free
resources, and in the case of (--cam->open_count == 0) we finish off by
doing a kfree(cam) and then at the end of the function we do a
mutex_unlock(&cam->busy_lock) which will explode since it'll dereference
the free'd `cam' :
...
mutex_lock(&cam->busy_lock);
...
if (--cam->open_count == 0) {
    ...
    if (!cam->present) {
        video_unregister_device(dev);
        kfree(cam);
    }
}
mutex_unlock(&cam->busy_lock);   <--- PROBLEM, cam no longer around.
...
Since this only happens in the case of open_count going down to zero I
don't see a problem with just releasing the mutex after unregistering the
device and just before the kfree().  In this case there is nothing around
that we can race against; we are in the release method, open_count is zero,
(!cam->present) and the device has just been unregistered, so letting go of
the mutex at this point looks safe to me.
Patch below to implement that solution.
Acked-by: Randy Dunlap <rdunlap@xenotime.net>

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-06-25 02:05:14 -03:00
Trent Piepho
657de3cd32 V4L/DVB (4118): Whitespace cleanups
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-06-25 02:05:10 -03:00
Mauro Carvalho Chehab
5e87efa3b2 V4L/DVB (4068): Removed all references to kernel stuff from videodev.h and videodev2.h
The videodev.h and videodev2.h describe the public API for V4L and V4L2.
It shouldn't have there any kernel-specific stuff. Those were moved to
v4l2-dev.h.
This patch removes some uneeded headers and include v4l2-common.h on all
V4L driver. This header includes device implementation of V4L2 API provided
on v4l2-dev.h as well as V4L2 internal ioctls that provides connections
between master driver and its i2c devices.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-06-25 02:05:05 -03:00
Randy Dunlap
fb9c280d4c V4L/DVB (3667b): cpia2: fix function prototype
Fix address space warning (from sparse):
drivers/media/video/cpia2/cpia2_core.c:2355:6: error: symbol 'cpia2_read' redeclared with different type (originally declared at drivers/media/video/cpia2/cpia2.h:458) - incompatible argument 2 (different address spaces)

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-04-02 05:02:33 -03:00
Alan Cox
2ae151911e V4L/DVB (3569): PATCH: switch cpia2 to mutexes and use ioctl 32 compat lib func
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-03-24 16:26:52 -03:00
Adrian Bunk
e690e14c94 V4L/DVB (3527): VIDEO_CPIA2 must depend on USB
CONFIG_VIDEO_CPIA2=y, CONFIG_USB=n results in the following compile
<--  snip  -->
...
  LD      .tmp_vmlinux1
drivers/built-in.o: In function `set_alternate':cpia2_usb.c:(.text+0x443aa2): undefined reference to `usb_set_interface'
drivers/built-in.o: In function `cpia2_usb_stream_resume': undefined reference to `usb_alloc_urb'
drivers/built-in.o: In function `cpia2_usb_stream_resume': undefined reference to `usb_submit_urb'
drivers/built-in.o: In function `cpia2_usb_stream_pause': undefined reference to `usb_kill_urb'
drivers/built-in.o: In function `cpia2_usb_stream_pause': undefined reference to `usb_free_urb'
drivers/built-in.o: In function `cpia2_usb_disconnect':cpia2_usb.c:(.text+0x443e14): undefined reference to `usb_driver_release_interface'
drivers/built-in.o: In function `cpia2_usb_transfer_cmd': undefined reference to `usb_control_msg'
drivers/built-in.o: In function `cpia2_usb_transfer_cmd': undefined reference to `usb_control_msg'
drivers/built-in.o: In function `cpia2_usb_complete':cpia2_usb.c:(.text+0x444836): undefined reference to `usb_submit_urb'
drivers/built-in.o: In function `cpia2_usb_cleanup': undefined reference to `usb_deregister'
drivers/built-in.o: In function `cpia2_usb_init': undefined reference to `usb_register_driver'

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-03-21 08:53:49 -08:00
Michael Krufky
49444fe123 V4L/DVB (3496): Cpia2: move Kconfig build logic into cpia2/Kconfig
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-03-21 08:53:24 -08:00
Alexey Dobriyan
be787ace01 V4L/DVB (3413): Typos grab bag of the month
Typos grab bag of the month.
Eyeballed by jmc@ in OpenBSD.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-03-08 12:04:24 -03:00
Adrian Bunk
8cbe84f33a V4L/DVB (3399a): cpia2/cpia2_v4l.c cleanups
- make 2 needlessly global functions static

- remove cpia2_setup(): the driver already allows setting parameters
  through module_param(), and there's no reason for having two different
  ways for setting the same parameters

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-03-03 12:15:29 -03:00
Alan Cox
ab33d5071d V4L/DVB (3376): Add cpia2 camera support
There has been a CPIA2 driver out of kernel for a long time and it has
been pretty clean for some time too. This is an import of the
sourceforge driver which has been stripped of
- 2.4 back compatibility
- 2.4 old style MJPEG ioctls
A couple of functions have been made static and the docs have been
repackaged into Documentation/video4linux.  The rvmalloc/free functions now
match the cpia driver again.  Other than that this is the code as is.
Tested on x86-64 with a QX5 microscope.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-02-27 00:09:05 -03:00